1. Technical Field of the Invention
This invention relates generally to broadcast traffic information, and more particularly to adjusting the amount of traffic information included in a traffic broadcast by using bounding areas.
2. Description of Related Art
Traffic information can be collected and transmitted to users via a packet switched network using Transport Protocol Experts Group (TPEG) frames, such as the Internet; by broadcasting Radio Data System (RDS) data; or using in-band-on-channel (IBOC) techniques, including digital audio broadcast (DAB) and HD™ radio broadcasts. Various IBOC techniques can be used to broadcast Transport Protocol Experts Group (TPEG) frames.
Current HD™ standards or implementations provide limited bandwidth for transmitting traffic information and other data. This limited bandwidth restricts the size of the payload that can be reliably delivered to vehicles in a broadcast area, and makes it difficult to expand traffic flow coverage to smaller roads, such as surface streets, in the broadcast area of large metropolitan areas. The inclusion of these smaller roads can be desirable to provide a better user experience for drivers and accurate time to destination.
Conventional systems define a single bounding area for each broadcast area, and that single bounding area is used to determine which sets of roads to include within broadcast TPEG frames within any given broadcast area. Use of a single bounding area can restrict coverage to only larger roads, which does not include most surface level streets. However, including traffic information for all of the smaller roads across the entire broadcast area can result in an increase in the amount of traffic data, and can cause the size of a TPEG frame payload to exceed size limitations imposed by current practices.
In view of the above, it is apparent that currently available technologies are less than perfect.